1450 XLD motherboard build, assorted questions
I've decided to try to build a 1450XLD from one of those 1450 motherboards that Best Electronics sells. I've been building up a BOM for the past two weeks working from the Atari schematic (lots of errors) as well as the Polish schematic (all the Atari errors, plus some new ones). I didn't see the Atari BOM until a few days ago, and it would have saved me a ton of time if I had started there instead, but I didn't know about it. In any event, it has errors too, but slightly fewer and different
I got impatient and soldered in Y2 where I thought it should go, and I now have signs of life! Unfortunately I still have some problems somewhere. I'm getting a picture, which is good, but it's going straight into memory test and showing the first ROM bar as red. All memory tests pass, and holding down Option shows 48 RAM squares as expected. Star Raiders cartridge works and I can play (although I don't have sound, but one problem at a time!).
I've swapped the OS ROM, reseated th
